U.S. patent number 5,408,686 [Application Number 07/969,013] was granted by the patent office on 1995-04-18 for apparatus and methods for music and lyrics broadcasting.
Invention is credited to Roy J. Mankovitz.
United States Patent |
5,408,686 |
Mankovitz |
April 18, 1995 |
Apparatus and methods for music and lyrics broadcasting
Abstract
A system for broadcasting audio music and broadcasting lyrics
for display and highlighting substantially simultaneously with the
occurrence of the lyrics in the accompanying audio music is
provided. The system includes a audio music source that provides a
data output and a analog audio signal output. A computer receives
the data output by the music source and generates lyric text data
and lyric timing commands. A subcarrier generator generates a
subcarrier signal carrying the lyric text data and lyric timing
commands. An FM transmitter broadcasts a composite signal that
combines the analog output of the music source with the subcarrier
signal. A lyric display unit receives the composite signal,
separates and decodes the subcarrier signal and displays and
highlights lyrics according the lyric text data and lyric timing
commands decoded from the subcarrier signal.
Inventors: |
Mankovitz; Roy J. (Encino,
CA) |
Family
ID: |
27417980 |
Appl.
No.: |
07/969,013 |
Filed: |
October 30, 1992 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
737211 |
Jul 29, 1991 |
5161251 |
Nov 3, 1992 |
|
|
657477 |
Feb 19, 1991 |
5134719 |
Jul 28, 1992 |
|
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Current U.S.
Class: |
455/66.1;
369/47.23; 370/528; 381/2; 455/3.06; 455/45; 455/67.11; 455/67.13;
455/67.16; G9B/27.019; G9B/27.021 |
Current CPC
Class: |
G11B
27/105 (20130101); G11B 27/11 (20130101); H04H
20/34 (20130101); H04H 20/48 (20130101); H04H
20/86 (20130101); H04H 60/73 (20130101); H04H
60/74 (20130101); G11B 2220/2545 (20130101); G11B
2220/65 (20130101) |
Current International
Class: |
G11B
27/11 (20060101); G11B 27/10 (20060101); H04H
1/00 (20060101); H04H 5/00 (20060101); H04B
001/00 () |
Field of
Search: |
;455/45,185.1,186.1,66
;381/2,4,6,14 ;370/110.1,110.4,111 ;369/6,33,47,48,86,92
;358/86,335,342,310 ;84/645 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Eisenzopf; Reinhard J.
Assistant Examiner: Pham; Chi H.
Attorney, Agent or Firm: Chrisite, Parker & Hale
Parent Case Text
BACKGROUND OF THE INVENTION
This is a continuation-in-part of pending patent application Ser.
No. 07/737,211 filed Jul. 29, 1991, which matured into U.S. Pat.
No. 5,161,251, issuing on Nov. 3, 1992, which is a divisional of
patent application Ser. No. 07/657,477, filed Feb. 19, 1991, which
matured into U.S. Pat. No. 5,134,719, issuing on Jul. 28, 1992.
Claims
What is claimed is:
1. A method of generating and transmitting data for use in
displaying lyrics of a musical selection and highlighting the
displayed lyrics at substantially the same time the lyrics occur in
a corresponding audible reproduction of such musical selection
comprising the steps of:
creating one or more files for storing lyric text and timing data
for a musical selection comprising the steps of:
separating the lyrics of such musical selection into phrases of
lyrics that are shorter than a predetermined length,
for each word occurring in a corresponding audible reproduction of
such musical selection, determining the length of time from a
predetermined temporal reference point in said musical selection to
the occurrence of such word in such corresponding reproduction of
such musical selection, and
storing the separated phrases of lyrics and representations of said
determined lengths of time for each word occurring in the musical
selection into said one or more files,
transmitting a reproduction of the musical selection over an analog
radio channel,
transmitting the text of each of said separated phrases of lyrics
stored in said one or more files prior to said predetermined
temporal reference point or within the determined length of time
for the first word of such phase after said predetermined temporal
reference point, and
for each of such phrases, transmitting highlight commands for each
word of such phrase when said determined length of time for such
word has elapsed since the occurrence of said predetermined
temporal reference point.
2. A method of generating and transmitting data for use in
displaying lyrics of a musical selection and highlighting the
displayed lyrics at substantially the same time the lyrics occur in
a corresponding audible reproduction of such musical selection
comprising the steps of
creating one or more files for storing lyric text and timing data
for a musical selection comprising the steps of:
separating the lyrics of such musical selection into phrases of
lyrics that are shorter than a predetermined length,
for each word occurring in a corresponding audible reproduction of
such musical selection, determining the length of time from a
predetermined temporal reference point in said musical selection to
the occurrence of such word in such corresponding reproduction of
such musical selection
storing the separated phrases of lyrics and representations of said
determined lengths of time for each word occurring in the musical
selection into said one or more files,
transmitting a reproduction of the musical selection over an analog
radio channel,
transmitting each word in said one or more files, its determined
length of time from said temporal reference point and a phrase code
if the word is the last word of a separated phrase, and
transmitting a command signifying the occurrence of said
predetermined temporal reference point.
3. The method of claim 2 wherein the step of transmitting each word
further comprises transmitting each word before the occurrence of
the predetermined temporal reference point.
Description
This invention relates to radio broadcast systems and, more
particularly, to apparatus and methods for identifying broadcast
audio program selections in FM stereo radio broadcast systems and
displaying lyrics of the audio program selections.
While FM broadcast station program materials generally consist of a
combination of music, news, advertising, and information programs,
the interest of a large segment of the listening audience is
directed to the music portion of the broadcasts. In fact, the music
industry cooperates with the radio stations and encourages the
broadcast of the latest album releases on the basis that most album
sales are the result of audience reaction to broadcast musical
selections.
One of the more frustrating aspects confronting the listener
concerns deciphering the lyrics of music selections received on the
radio. Often the lyrics of vocal music, from modern popular music
to classical music, are difficult to understand, even after the
selection is heard many times. It is sometimes possible for a
listener to obtain lyrics by buying the compact disc (CD) on which
the selection is included. However, many compact discs do not
include printed lyrics and the listener has no way to know before
buying the CD whether lyrics are included. Further, the listener
must buy the whole CD on which the selection is included just to
get the lyrics of the one desired selection.
Even if printed lyrics are obtained by the listener, the printed
lyrics do not indicate when the individual words are sung in
relation to the music contained on the CD. One way of solving this
problem are video sing-along systems such as "karaoke" systems.
These self-contained systems reproduce musical selections, often
with the lead vocal omitted and display lyrics on video screens.
These systems involve expensive equipment and require the
additional purchase of special recordings of musical selection that
often can be only used with the sing-along systems.
Another source of frustration is the identification of the
broadcast musical selections, particularly since the stations do
not employ a uniform method of identification. Some stations
announce the titles of a group of selections prior to their
broadcast, others announce the titles after the broadcast of such a
group, while still others provide such announcements on a random
basis. Rarely do the stations announce the title, artist and album
information for each selection. The result is that the listener is
generally unable to rapidly identify and remember a particular
musical selection with sufficient accuracy to enable the subsequent
purchase of the album containing that selection.
The present invention provides an apparatus and methods for
storing, broadcasting, receiving and displaying lyrics of music
being simultaneously broadcast, including a real time indication of
when each word or phrase of the lyrics is being sung in the
accompanying musical broadcast.
The present invention also provides apparatus and methods for
enabling a listener to rapidly and accurately identify broadcast
musical selections.
The invention also provides apparatus and methods of storing
selected musical selection identification information, and for
recalling such information at a later time, to facilitate the
purchase of the album containing that selection.
In order to make the broadcast of the lyric and identification
material commercially feasible, the invention provides apparatus
and methods for receiving and storing supplemental commercial text
data substantially concurrently with the reception of audio
commercial messages.
SUMMARY OF THE INVENTION
A broadcast system is provided which is compatible with
conventional FM stereo receivers and which includes transmitter
apparatus for transmitting audio musical selections and auxiliary
data in the form of a digital message signal representing a text
message which includes the name of the musical selection, name of
the artist performing the selection, the name of the album on which
the selection is located, the lyrics of the musical selection and
timing data for synchronizing the lyrics with the music. The text
message is transmitted either during, immediately prior to or
immediately after the transmission of the musical selection.
Receiver apparatus receives the musical selection and the digital
message signal. The musical selection is reproduced using
loudspeakers and the like, and the message signal is decoded into
the text messages which are displayed on a display substantially
concurrent with the reproduction of the musical selection.
A user operated storage feature is provided for storing the
displayed text message, and for recalling it for display at a later
time. In another embodiment, the storage feature also stores a
portion of the musical selection along with the text message
identifying that selection. Upon recall, the stored musical
selection is reproduced while the stored message is displayed.
Multiple text messages and corresponding musical selections may be
stored and recalled by user operation of multiple control switches,
which may be the same control switches used in a conventional
digitally tuned receiver for storing and recalling broadcast
station frequencies.
A system for transmitting the auxiliary data is also disclosed
where the musical selections and auxiliary data are transmitted as
part of an FM stereophonic broadcast system in which a main carrier
is transmitted at an assigned broadcast station frequency. An audio
sum signal is provided representing the sum of the left and right
channels of the stereophonic audio programs, and a double sideband
suppressed carrier (DSBSC) signal is provided where the suppressed
carrier is amplitude modulated by an audio difference signal
representing the difference between the left and right channels of
the stereophonic audio programs, the frequency of the suppressed
carrier being such that the frequency spectra of the DSBSC signal
is spaced apart from and is above the frequency spectra of the
audio sum signal.
A stereo pilot subcarrier is provided to demodulate the DSBSC
signal in receiver apparatus, where the frequency of the pilot
subcarrier is a subharmonic of the DSBSC signal and is located
between the frequency spectra of the audio sum signal and the DSBSC
signal. Circuits are provided for amplitude modulating the stereo
pilot subcarrier with the auxiliary data, and a modulator is used
for frequency modulating the main carrier with the audio sum
signal, the modulated stereo pilot subcarrier, and the DSBSC
signal.
In one version of the above system, the auxiliary data is
transmitted during the transmission of the stereo musical
selections, and the stereo pilot subcarrier is amplitude modulated
in a manner such that the frequency spectra of the modulated pilot
does not overlap the frequency spectra of the audio sum signal or
the frequency spectra of the DSBSC signal. When amplitude modulated
with the auxiliary data, the stereo pilot subcarrier frequency
modulates that main carrier from a minimum of 8% to a maximum of
10% of a predetermined maximum frequency modulation of the main
carrier.
In another embodiment of the invention, the auxiliary data is
transmitted during at least one time interval either before or
after the transmission of the stereo musical selections. During
that interval, which may be an interval of silence or in which
audio announcements are transmitted, the left and right channels of
the audio material being broadcast are set substantially equal to
each other, forming a monophonic signal whereby the DSBSC signal is
substantially unmodulated. The auxiliary data is transmitted during
that interval by amplitude modulating the pilot subcarrier up to
100% with the auxiliary data, and the modulated subcarrier in turn
frequency modulates that main carrier up to 30% of a predetermined
maximum frequency modulation of the main carrier.
In another version of the above embodiment the auxiliary data is
again transmitted during at least one monophonic time interval
either before or after the transmission of the stereo musical
selections, when the DSBSC signal is substantially unmodulated. In
this version, the stereo pilot subcarrier is not modulated with the
auxiliary data. Instead, the stereo pilot subcarrier is suppressed
during the monophonic transmission interval, and an auxiliary data
subcarrier is provided having a frequency greater than the
frequency of the stereo pilot subcarrier and less than or equal to
the highest frequency of the DSBSC signal spectra, and which is
amplitude modulated by the auxiliary data. The auxiliary data
subcarrier frequency may be set equal to the frequency of the DSBSC
signal.
Also provided is a modulator for frequency modulating the main
carrier with the audio sum signal, the stereo pilot subcarrier, the
DSBSC signal, and the amplitude modulated auxiliary data
subcarrier.
A receiver is disclosed for receiving the frequency modulated main
carrier, and for using the amplitude modulation of the stereo pilot
subcarrier (or the auxiliary data subcarrier) to provide the
auxiliary data.
Also disclosed is a system for automatically providing an audio
musical selection and a digital message signal representing a text
message which includes the name of the musical selection, the name
of the artist performing the selection, and the name of the album
on which the selection appears. The system includes a compact disc
player for playing a compact disc having multiple tracks each of
which contains digitized musical data representing an audio musical
selection.
The disc when played by the player provides, in addition to the
audio musical selection, a track identification signal identifying
the track being played and a disc identification signal which
uniquely identifies the disc from other compact discs. A digital
processor is provided with a memory having stored therein a table
which includes the disc identification signal along with the name
of the artist performing the musical selections on that disc and
the name of the album on which the selection appears. The table
also includes the names of the musical selections contained on that
disc along with the track on which each selection is contained.
The processor is responsive to the disc identification signal and
the track identification signal from the player and uses those
signals in conjunction with the stored table for determining the
name of the performing artist, the name of the album, and the name
of the musical selection, and for combining these names to form the
digital message signal.
A method of identifying broadcast audio program selections is
disclosed which includes the steps of receiving a plurality of
broadcast audio program selections which are reproduced by audio
transducer means; receiving a plurality of broadcast text messages,
where each text message is received substantially concurrent with
and identifies a corresponding one of the audio program selections;
temporarily storing a broadcast text message while it is being
received, in a manner where each received text message replaces the
previously temporarily stored text message; selecting in response
to a user storage command a text message and a portion of the
broadcast audio program identified by the selected text message to
be stored in a fixed manner where it is retained until selected for
deletion by user action; storing the selected text message and the
selected portion of the broadcast audio program until it is
selected for deletion by user action; providing a display for
displaying a text message; recalling the selected text message in
response to a user recall command; and displaying the recalled
message on the display.
A method for transmitting a plurality of stereophonic audio
programs and auxiliary data is disclosed which includes the steps
of transmitting a main carrier at an assigned broadcast station
frequency; providing an audio sum signal representing the sum of
the left and right channels of the stereophonic audio programs;
providing double sideband suppressed carrier (DSBSC) signal, where
the suppressed carrier is amplitude modulated by an audio
difference signal representing the difference between the left and
right channels of the stereophonic audio programs, the frequency of
the suppressed carrier being such that the frequency spectra of the
DSBSC signal is spaced apart from and is above the frequency
spectra of the audio sum signal; providing a stereo pilot
subcarrier to be used to demodulate the DSBSC signal in receiver
apparatus, where the frequency of the pilot subcarrier is a
subharmonic of the DSBSC suppressed carrier and is located between
the frequency spectra of the audio sum signal and the DSBSC signal;
amplitude modulating the stereo pilot subcarrier with the auxiliary
data; and frequency modulating the main carrier with the audio sum
signal, the modulated stereo pilot subcarrier, and the DSBSC
signal.
Another method is disclosed for stereophonically transmitting a
series of stereophonic audio programs comprised of left and right
channels, and auxiliary data, including the steps of providing
monophonic intervals spaced between stereophonic audio programs,
where the left and right channels are substantially equal;
transmitting a main carrier at an assigned broadcast station
frequency; providing an audio sum signal representing the sum of
the left and right channels of the stereophonic audio programs;
providing a double sideband suppressed carrier (DSBSC) signal,
where the suppressed carrier is amplitude modulated by an audio
difference signal representing the difference between the left and
right channels of the stereophonic audio programs, the frequency of
the suppressed carrier being such that the frequency spectra of the
DSBSC signal is spaced apart from and is above the frequency
spectra of the audio sum signal; providing during stereophonic
transmissions a stereo pilot subcarrier to be used to demodulate
the DSBSC signal in receiver apparatus, where the frequency of the
pilot subcarrier is a subharmonic of the DSBSC signal frequency and
is located between the frequency spectra of the audio sum signal
and the DSBSC signal; suppressing the stereo pilot subcarrier
during at least one monophonic interval; providing during the at
least one monophonic interval an auxiliary data subcarrier having a
frequency greater than the frequency of the pilot subcarrier and
less than or equal to the highest frequency of the DSBSC signal
spectra; amplitude modulating the auxiliary data subcarrier by the
auxiliary data; and frequency modulating the main carrier with the
audio sum signal, the stereo pilot subcarrier, the DSBSC signal,
and the amplitude modulated auxiliary data subcarrier.
Also disclosed is a method of identifying audio broadcast programs,
including the steps of: providing an audio musical selection;
providing a digital message signal representing a text message
which includes the name of the musical section and the name of the
artist performing the selection; transmitting the digital message
signal and the audio musical program, where the digital message
signal is transmitted substantially concurrent with the
transmission of the audio musical selection; receiving the audio
musical selection and the digital message signal; decoding the
digital message signal into the text message; reproducing the audio
selection using audio transducer means; and displaying the text
message substantially concurrent with the reproduction of the
musical selection.
A system for storing, broadcasting, receiving and displaying lyrics
of music substantially simultaneously with the broadcast of the
audio music itself is also disclosed. Phrases of lyrics are
broadcast, received and displayed just before or as the phrases of
lyrics occur in the accompanying music. Further, once a phrase is
displayed individual words or lines of the phrase are highlighted
as the particular word or line occurs in the accompanying music.
Several systems and methods for creating the lyric and timing data
necessary for the broadcasting, display and highlighting of lyrics
is also disclosed.
The system also provides for preparing, broadcasting, receiving and
displaying supplemental text provided by advertisers. The
supplemental advertising text is broadcast and displayed
substantially simultaneously with the broadcast of a corresponding
audio commercial message. This supplemental advertising text can be
output to a printer or stored in memory by a user for later
reference.
These and other objects, features and advantages of the invention
will become apparent from a reading of the specification when taken
in conjunction with the drawings on which like reference numerals
refer to like elements in the several figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of an FM stereo transmitter
system constructed in accordance with the invention showing pulse
amplitude modulation of the stereo pilot subcarrier to broadcast
auxiliary digital data in addition to audio program material;
FIG. 2 is a graph showing the frequency spectra and relative
modulation levels of the main station carrier in response to the
various signals transmitted by the transmitter of FIG. 1 within the
broadcast channel of an FM stereo broadcast station in accordance
with a first embodiment of the invention;
FIG. 3 is a graph showing the pulse amplitude modulation of the
stereo pilot carrier in the time domain when used to transmit
auxiliary digital data in accordance with the first embodiment of
the invention;
FIG. 4 is a functional block diagram of an FM stereo receiver
constructed in accordance with the invention for receiving,
displaying, storing and recalling the auxiliary digital data
transmitted by the transmitter of FIG. 1;
FIG. 5 is a graph showing the frequency spectra and relative
modulation levels of the main station carrier in response to the
carrier signals transmitted by the transmitter of FIG. 1 within the
broadcast channel of an FM stereo broadcast station in accordance
with a second embodiment of the invention which transmits auxiliary
digital data during periods of monophonic audio transmission;
FIG. 6 is a graph showing the pulse amplitude modulation of the
stereo pilot carrier in the time domain when used to transmit
auxiliary digital data in accordance with the second embodiment of
the invention;
FIG. 7 is a functional block diagram showing a modification of the
transmitter of FIG. 1 to pulse amplitude modulate a 38 kHz
auxiliary data subcarrier to transmit auxiliary digital data during
monophonic audio transmission;
FIG. 8 is a functional block diagram showing a modification of the
receiver of FIG. 4 to demodulate the auxiliary data subcarrier
transmitted using the modification of FIG. 7; and
FIG. 9 is a functional block diagram showing the use of a compact
disc player and a digital processor for automatically providing the
auxiliary digital data signal for transmission by the transmitter
of FIG. 1, where the data signal represents the title, artist and
album corresponding to the musical selection being played by the
player.
FIG. 10 is a block diagram of a system for broadcasting lyric
information corresponding to music being broadcast
simultaneously.
FIG. 11 is an external view of a lyric receiver and display
unit.
FIG. 12 is a block schematic of a lyric receiver and display
unit.
FIG. 13 is a block diagram of a system for creating files that
store both lyrics and lyric timing data.
FIG. 14 is a depiction of the prior art method of converting
commercial messages to a form useful to radio stations.
FIG. 15 is a block diagram showing a system for embedding digital
data that supplements commercial messages onto tape cartridges used
by radio stations to store the main commercial messages.
FIG. 16 is a block diagram showing a system for decoding and
broadcasting the digital data embedded onto a tape cartridge
according to the system of FIG. 15.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
Several prior art systems have been developed for use with
conventional FM stereo broadcast systems for the transmission and
reception of data (hereinafter referred to as auxiliary data) which
is not a part of the regularly broadcast stereophonic audio
programs. In general, these systems employ one or more subcarriers
which are transmitted in a subcarrier band (generally referred to
as the SCA band) which lies above the 53 kHz portion of the station
bandwidth allocated to the transmission of conventional stereo
audio signals. A variety of techniques are used to modulate these
subcarriers to transmit auxiliary data which may be in the form of
additional audio programs, or special announcements such as traffic
conditions.
Examples of the above described systems are disclosed in U.S. Pat.
Nos. 3,949,401; 4,435,843; 4,450,589 and 4,584,708, all assigned to
Blaupunkt-Werke GmbH; and U.S. Pat. Nos. 4,252,995; 4,393,273; and
4,538,285, all assigned to U.S. Philips Corporation.
One drawback in these prior art auxiliary data transmission systems
is that by using the SCA band for such use, they preclude the
broadcast station from using that band for other uses such as the
broadcast of background music, foreign languages, financial data,
and the like, all of which can provide substantial additional
income to the station. Further, the use of this band poses
substantial technical problems due to the low frequency modulation
limits imposed for this band by regulations, and due to the
relatively high FM modulation frequencies required to operate in
this band. These limitations result in a low signal-to-noise ratio,
requiring complicated and expensive modulation and noise reduction
circuitry. As shown below, the present invention overcomes these
problems by using the stereo audio portion of the station broadcast
band for transmission of the auxiliary data.
Referring to FIG. 1, there is shown a functional block diagram of
an FM stereo transmitter system 10 constructed in accordance with
the teachings of the invention. Left and right channel audio
signals from a stereophonic audio source (such as a compact disc
player or microphone) are provided on lines 12 and 14 to
pre-emphasis networks 16 and 18, respectively. These networks add
pre-emphasis and limit signal bandwidth to 50 Hz-15 kHz.
The signal from the network 16 is provided to an input terminal of
adders 20 and 22 (which form part of a matrix network), while the
signal from the network 18 is provided to an input terminal of
adder 20 and, through an inverter 24, to an input terminal of adder
22. The signal from the adder 20, representing a monaural signal in
the form of the sum (L+R) of the left and right audio channels is
provided on line 25 to an input terminal of a linear combining
network 26 through a delay network 28. The signal from the adder
22, representing the difference (L-R) of the left and right audio
channels, is provided to the input terminal of a balanced modulator
30. The output signal from the modulator 30 which, as described
below, is in the form of a double sideband suppressed carrier
(DSBSC) signal, is provided on line 31 to a second input terminal
of the combining network 26.
A 19 kHz oscillator 32 provides a 19 kHz stereo pilot signal on
line 34 to a phase locked loop (PLL) circuit 36 which uses the
pilot signal to generate a phase synchronized 38 kHz signal on line
38. The signal on line 38 is provided as a carrier signal to the
modulator 30 which, in a well known manner, generates the DSBSC
signal having a suppressed carrier at 38 kHz which is amplitude
modulated by the L-R signal to form upper and lower sidebands, each
having a 15 kHz bandwidth. Thus, the frequency spectra of the DSBSC
signal extends from 23 to 53 kHz. The stereo pilot is used in
receiver apparatus described below to demodulate the DSBSC
signal.
The 19 kHz signal from the oscillator 32 is provided on line 40 to
the input terminal of a variable gain amplifier 42, the output
signal of which is provided as a stereo pilot subcarrier on line 44
to a third input terminal of the combining network 26. An optional
SCA (Subsidiary Communications Authorization) signal is provided on
line 46 to a fourth input terminal of the network 26. The SCA
signal may include background music, foreign language, financial
data and other generally commercial-free programming materials
which are broadcast to subscribers having special receivers. The
SCA band is generally limited to the 59.5 to 74.5 kHz portion of
the broadcast channel.
The output signal from the combining network 26 is provided to an
FM modulator 48 which is used to frequency modulate a main carrier
provided by transmitter 50 to antenna 52 at the assigned broadcast
station frequency. The combining network 26 is used in part to set
the FM modulation levels produced by the various input signals. In
accordance with the teachings of the invention, the gain settings
of the variable gain amplifier 42 also affect the FM modulation
levels produced by the 19 kHz stereo pilot subcarrier as described
below.
FM broadcast station frequencies in the United States are in the
band from 88 to 108 MHz. Each station is allocated a 200 kHz wide
channel, and FM modulation levels of the various broadcast signals
are referenced as a percent of a 75 kHz frequency deviation, which
is defined as the 100%, or maximum, FM modulation level.
Hereinafter, references to FM signal percent modulation levels are
with respect to this 100% level.
The portion of the transmitter system 10 described thus far
(excepting the operation of the variable gain amplifier 42)
represents a conventional FM stereo broadcast system well known to
those skilled in the art. FIG. 2 is a graph showing the frequency
spectra and relative FM modulation levels (%) of the main carrier
produced by the various signals previously described. The L+R
monaural signal from line 25 of FIG. 1 occupies the 50 Hz to 15 kHz
spectra and FM modulates the main carrier up to a level of about
40%. The 19 kHz stereo pilot subcarrier FM modulates the main
carrier at a nominal level of 9%, and is constrained by FCC
regulations to the range of 8-10% during stereo broadcasts. The
DSBSC Signal from the line 31 of FIG. 1 occupies the 23-53 kHz
spectra (.+-.15 kHz about the 38 kHz suppressed carrier), and FM
modulates the main carrier up to a level of about 40% during
stereophonic broadcasts. The SCA signal from the line 46 occupies
the 59.5-74.5 kHz spectra, and FM modulates the main carrier up to
a level of about 10%.
Returning to FIG. 1, the following components are added to the
conventional transmitter system described above to enable the
broadcast of auxiliary digital data used to identify musical
selections. A data source 54 is provided which produces a signal on
line 56 which identifies a particular stereophonic musical
selection provided on lines 12 and 14 for broadcast. The signal on
line 56, which is preferably a digital signal, is provided to an
input terminal of a code generator 58, the purpose of which is to
arrange the input signal into a text message in the form of a pulse
code sequence where the pulses are of a predetermined amplitude and
frequency.
In response to a start signal appearing on line 60, the code
generator 58 provides the pulse code sequence on line 62 to a gain
control input terminal of amplifier 42. The amplifier 42 responds
to the gain control signal by varying the amplitude of the 19 kHz
signal provided on line 44 to the network 26. In effect, the pulse
code sequence on line 62 in conjunction with amplifier 42 provides
pulse amplitude modulation (PAM) of the broadcast stereo pilot
subcarrier.
Preferably, the text message is broadcast substantially concurrent
with the broadcast of the musical selection which it identifies.
The term "substantially concurrent" as used herein is meant to
include substantially immediately prior to, during, or
substantially immediately after the broadcast of the musical
selection. By way of example but not limitation, the signal
provided on line 56 by the data source 54 includes three items of
information: the title, the name of the performing artist, and the
name of the album corresponding to the musical selection to be
identified. The generator 58 arranges this information into the
form of a three-line text message suitable for display on three
lines of a digital display which is included in receiver circuits
described below.
By way of further example, each of the three items of information
is allocated 24 characters. A six-bit ASCII code may be used to
represent the characters, for a total of 432 character bits. Adding
additional bits for start-of-message (SOM), end-of-message (EOM),
carriage return, and error correction codes results in a
requirements for about 500 bits of information to represent the
entire message. Using pulse amplitude modulation of the stereo
pilot subcarrier, these 500 bits are transmitted by the system 10
using 250 pulse code cycles as follows.
The steady-state gain of the amplifier 42 in the absence of a gain
signal on the line 62 is set so that the 19 kHz stereo pilot signal
on the line 44 FM modulates the main carrier at a 9% modulation
level. In response to the start signal on the line 60, the
generator 58 provides a sequence of pulses on the line 62 which
represent the message corresponding to the data from the source 54.
The pulse sequence preferably begins with an SOM code word, and
ends with an EOM code word. The pulses, which are preferably in the
form of binary ones and zeros, act to vary the gain of the
amplifier 42, and thus the amplitude of the signal 44, whereby the
stereo pilot signal FM modulates the main carrier in the range of 8
to 10% in response to these pulses. This modulation envelope is
shown in the frequency spectra by dotted line 64 in FIG. 2, and is
shown in the time domain by the graph of FIG. 3.
In FIG. 3, the amplitude of the stereo pilot signal is shown as
decreasing from a 9% FM modulation level to 8% in response to a
pulse on the line 62 representing a binary zero, and increasing to
a 10% level in response to a pulse on the line 62 representing a
binary one. Accordingly, the pulses act to amplitude modulate the
stereo pilot by an amount of about 11% AM modulation. The
repetition rate at which the pulse sequence is provided on the line
62 is determined in part by the timing relationship between the
broadcast of a musical selection and the broadcast of the message
identifying that selection, as follows.
It is presumed that the broadcast station transmits a plurality of
stereophonic musical selections which are separated from each other
by an interval of silence of about one second or more, or are
separated by audio announcements of much longer duration. The
duration of most musical selections is generally one minute or
more.
One protocol for broadcasting the digital message is to transmit it
during the time the corresponding musical selection is being
transmitted, where the message transmission begins at about the
same time as the musical selection transmission begins. Using this
protocol, it is desirable to minimize the AM modulation frequency
of the stereo pilot signal to avoid AM sideband disturbance to
receiver circuits (described below) which use that signal to
demodulate the L-R signal. This can be accomplished by transmitting
the message at a low data rate over an interval of, for example, 25
seconds. This interval is sufficiently short to permit the entire
message to be transmitted before the end of the musical selection
which it identifies. The 25 second interval yields a pulse rate of
10 Hz to transmit the 250 pulse cycles constituting the message. It
is envisioned that this low frequency will not interfere with
conventional receiver operation relating to stereophonic signal
reception.
Another protocol for broadcasting the digital message is to
transmit it during the interval of silence immediately preceding or
following the musical selection to be identified. Using this
protocol, it is envisioned that the message would be transmitted
within approximately one second. A higher message transmission data
rate can be used during this interval of silence because minor
disturbances in the demodulation function of the stereo pilot
signal in the receiver can be tolerated due to the fact that no
audio signals are being received.
From FIG. 2, it will be seen that the stereo pilot is separated
from the audio signals by a 4 kHz band, and it is desirable to keep
the stereo pilot AM sidebands well within this band between the L+R
and L-R signal spectra to avoid spurious tone generation in the
receiver. Accordingly, a pulse repetition rate of, for example, 1
kHz may be chosen to transmit the digital message in 250
milliseconds, which is well within the interval of silence.
Referring now to FIG. 4, there is shown a receiver system 70 which
may be used to receive the stereophonic audio broadcasts as Well as
the digital message signals transmitted by the transmitter system
10. The system 70 includes conventional RF amplifiers, converter,
IF amplifiers and limiter, (all shown in block 72) for receiving FM
signals via antenna 73 in a standard FM receiver. The output signal
from the block 72 is provided to an FM detector 74, the output of
which is provided to filters 76, 78, and 80. The filter 76 is a 50
Hz-15 kHz low pass filter for extracting the monaural L+R signal
from the received composite signal. The L+R signal is provided to
an input terminal of a matrix and de-emphasis network 82.
The filter 78 is a 23-53 kHz bandpass filter for extracting the
DSBSC L-R signal from the received composite signal. The L-R signal
is provided on line 83 to a signal input terminal of an AM detector
84. The filter 80 is a 19 kHz bandpass filter for extracting the
stereo pilot signal from the received composite signal. The pilot
signal is provided on line 86 to a phase locked loop (PLL) 88. In
response thereto, the PLL 88 provides a 38 kHz signal which is
synchronized to the phase of the pilot signal.
This 38 kHz signal is provided to a carrier input terminal of the
AM detector 84. The output signal from the detector 84 is provided,
through low pass filter 90 to another input terminal of the network
82. Output signals from the network 82 are provided to left and
right channel audio amplifiers 92 and 94, respectively. Output
signals from the amplifiers 92,94 are used to drive audio
transducers, which may be in the form of loudspeakers 96 and 98,
respectfully.
A control panel 100 is provided which includes a variety of user
operated controls including digital tuning controls. An up/down
tuning switch 102 is used to change the tuning frequency of the
receiver by providing a tuning signal on line 104 which is used to
control the RF and converter circuits in the block 72 in the well
known manner of a superheterodyne receiver. The switch 102 enables
the user to scan up or down the FM band to select a desired
broadcast station frequency.
The frequency to which the receiver is tuned is shown on a display
106 (which may be of the liquid crystal type) by providing a
suitable frequency indicating signal on line 108 to an input
terminal of display control, coding and storage circuits 110. The
circuits 110 are used to code the incoming signals into display
characters, and to store those characters until they are replaced
by new ones in response to a change in the incoming signal. The
stored characters are provided to the display 106 on bus 112. The
display in FIG. 4 shows the receiver tuned to 104.7 MHz.
In addition to the switch 102, the panel 100 includes a plurality
of switches 114 (labeled 1 through 5 in the Figure) which are used
in conjunction with a memory switch 116 to store often used station
frequencies. Storage is accomplished by tuning the receiver to the
desired frequency using the switch 102, pressing the memory switch
116, and then pressing one of the switches 114. These steps act to
store the tuned frequency in a storage location corresponding to
the particular switch 114 actuated. Future actuation of the
switches 114 acts to recall the previously stored station
frequency, which is displayed on the display 106 and used to tune
the receiver 70.
The operation of the receiver circuits described thus far for the
reception of stereophonic audio signals is as follows. The receiver
is tuned to the desired station frequency using the switches 102 or
114 as described above. The received signal is processed by the
circuits 72 and 74, and separated by the filters 76, 78 and 80 into
the L+R, L-R and stereo pilot signals, respectively. The stereo
pilot signal is used to reconstruct the 38 kHz subcarrier, which is
used by the AM detector 84 to demodulate the L-R signal. The L+R
and L-R audio signals are combined by the matrix network 82 to form
left and right audio signals on lines 89 and 91, which are
amplified and reproduced by the elements 92, 94, 96 and 98 to
produce stereophonic sound. The presence of the stereo pilot signal
may be used to illuminate a stereo indicator light (not shown).
If the broadcast station is transmitting monophonically, the stereo
pilot signal is generally not transmitted. In this event, the
stereo indicator is extinguished, no L-R signal is present, and the
matrix network 82 provides the monophonic L+R signal to the
amplifiers and speakers to reproduce monophonic sound.
The receiver system 70 also receives and processes the auxiliary
data (in the form of a digital message signal) transmitted by the
system 10 as described above to identify musical selections
broadcast and reproduced substantially concurrently therewith. This
is accomplished by an amplitude demodulator 118 which receives at
its input terminal from the filter 80 the stereo pilot signal,
which is pulse amplitude modulated (PAM) with the digital message
signal. The bandwidth of the filter 80 is set sufficiently wide to
accommodate the PAM sidebands, which may typically range from 10 Hz
to 1 kHz, depending on the procedure used in broadcasting the
message, as described above. Alternatively, a separate 19 kHz
bandpass filter (not shown) may be employed between the detector 74
and the demodulator 118, if it is desired to maintain a very narrow
bandwidth for the filter 80 in connection with the operation of the
PLL 88.
The demodulator 118 may be configured in a variety of ways, one
example of which is shown in FIG. 4.2.23 of the textbook entitled
"Digital Communications", written by John G. Proakis, McGraw-Hill,
1983. The output signal from the demodulator 118, which contains
the pulse sequence representing the digital message, is provided on
line 119 to a data input terminal of a digital processor 120, which
is preferably in the form of a microprocessor. A non-volatile
random access memory 122 is also connected to the processor 120 via
bus 124. The memory 122 is of the type which retains data stored
therein even upon removal of power from the remaining receiver
circuits, using any of a plurality of well known techniques.
Upon receipt of an SOM code word on the line 119, the processor 120
begins storing the message in a temporary storage area which may be
a part of the processor 120. This area is labeled temporary because
subsequent received messages are automatically stored therein in
place of previously received messages, as described below. Upon
receipt of an EOM code word on the line 119, the processor 120
provides the message, corrected for errors using suitable error
correction techniques, to the display 106 via a display output
terminal and bus 126.
The display 106 is configured with four display lines. One line is
used as described above to display tuning frequency in response to
data from the circuits 110, which are preferably included as part
of the processor 120. The additional three display lines are used
to display the musical selection title, artist and album,
respectively, in response to the signals on the bus 126. Upon
receipt of a subsequent SOM code word, the processor 120 clears the
temporary storage area and the three lines of the display,
temporarily stores the new message in place of the previous
message, and upon receipt of an EOM code word, displays that new
message. Alternatively, incoming messages may be displayed as they
are being received, as opposed to being displayed after they are
received.
From the above description, it may be seen that the receiver system
70 displays to the user a message identifying a musical selection
broadcast and reproduced by the speakers 96,98 substantially
concurrent therewith. Further, the system 10 used to transmit the
message is compatible with existing FM stereo receivers in that it
does not disturb the reception and processing of the stereophonic
audio signals. This is so because such receivers are, for the most
part, insensitive to the amplitude modulation of the stereo pilot
signal within the limits described above. For example, while the
PLL 88 uses the phase information from the received stereo pilot to
reconstitute the 38 kHz carrier, it is relatively unaffected by
amplitude changes in the pilot signal.
One limitation in the system 70 described above is that the user
must observe the display 106 during the reception of the musical
selection associated therewith in order to note the identifying
information. First, this limitation poses a problem in automobile
radios, where such action disrupts the drivers attention. Second,
this limitation requires that the user remember or note in writing
the identifying information if the intention is to purchase at a
later time the album containing that selection.
This limitation is overcome in the present invention by providing a
fixed storage function for storing selected messages for recall at
a later time in response to user action. Thus, a SAVE button 128 is
provided on the control panel 100, the actuation of which provides
a store signal to an input terminal of the controller 120 via line
130. In response to this signal, the controller 120 acts to store
the displayed message in a non-volatile portion of the memory 122
for later recall by the user. Multiple messages may be saved in
this manner by combining the function of the switch 128 with the
switches 114 as follows.
In order to save a message, the user actuates the SAVE switch 128
followed by one of the switches 114 used for storing and recalling
station frequencies, as described above. Using this sequence of
switch actuations, the processor 120 receives a select signal on
line 132 representing a particular one of the switches 114 thus
actuated, in addition to the store signal on the line 130. In
response thereto, the processor 120 stores the displayed message in
a memory location whose address correlates with the particular
switch 114 actuated.
Thus, in the configuration shown, up to five separate messages may
be stored by the user in separate locations in the memory 122. More
messages may be accommodated by providing additional switches 114
on the panel 100. To recall a particular message at a later time,
the user actuates a RECALL switch 136 provided on the panel 100,
followed by the actuation of one of the switches 114. This action
causes the processor 120, in response to a recall signal provided
on line 136, and a select signal on line 132, to recall the
selected message previously stored in the memory 122, and to
display that message on the display 106.
Such stored messages may be repeatedly recalled until deleted by
the user. Deletion is accomplished by actuation a delete switch 138
provided on the panel 100, followed by actuation of one of the
switches 114. This action causes the processor 120, in response to
a delete signal provided on line 140 and a select signal on line
132, to delete from the memory 122 the selected message.
Indicator lights 142 may be provided on the panel 100 adjacent each
switch 114 to indicate which switch locations have messages stored
in conjunction therewith. Thus, the user can see which locations
are free for storage of additional messages. The lights 142 are
controlled by the processor 120 via line 133. Further, an audio
tone can be provided by the processor 120 to alert the user in the
event a location is chosen for storage of a new message and that
location already contains a previously stored message. In response
to that tone, the user can select another location, or delete the
previously stored message from that location. This procedure
eliminates the accidental deletion of a previously stored message.
The use of an audio tone also eliminates the need for the user to
look at the display panel prior to storing messages. A suitable
switching arrangement (not shown) can be implemented to suppress
the display of incoming messages during the time when previously
stored messages are being recalled.
It will be appreciated that the features described above eliminate
the need for the user to memorize or note in writing messages of
interest. They can be selected and stored, and then recalled and
displayed at a later time such as just prior to purchase of the
album. There are occasions, however, when upon later recall of a
message, the user can no longer remember the melody and/or lyrics
of the musical selection associated with that message. This is
particularly true when a plurality of messages have been
stored.
To overcome this problem, the system 70 includes apparatus for
storing a portion of the musical selection along with the message
identifying that selection. Referring to FIG. 4, an analog to
digital (A/D) converter 144 is provided having an input terminal
connected to, for example, line 91 to receive audio signals from
one (left or right) of the stereophonic channels provided by the
network 82. A digital output signal representing the received audio
program is provided by A/D converter 144 on line 146 to a music
input terminal of the processor 120. A digital to analog (D/A)
converter 148 is provided having an input terminal connected via
line 150 to a music output terminal of the processor 120, and
having an analog output signal terminal connected via line 152 to a
second audio input terminal of the amplifier 94.
The operation of this portion of the system 70 is as follows. Upon
listening to a musical selection reproduced by the system 70, if
the listener desires to save information concerning that selection,
the switches 128 and 114 are actuated as described above. In
response thereto, the processor substantially immediately begins
storing in the non-volatile portion of the memory 122 the digital
signals received on line 146 from converter 144, and continues the
storage of such signals for a predetermined interval of time, for
example, ten seconds. The processor also stores in an associated
portion of the memory 122 the message corresponding to that musical
selection. As stated above, the digital signals on the line 146 are
a representation of the audio selection being broadcast. It has
been found that ten seconds is generally a sufficient interval of
time to enable the user to identify the lyrics and/or the melody of
most musical selections.
Upon recall of the stored information using switches 136 and 114,
the processor 120 provides the stored message to the display 106
and substantially simultaneously provides the digital signals
previously stored from the converter 144 to the input terminal of
the converter 148 on the line 150. The converter 148 converts these
signals to an analog signal representing ten seconds of the musical
selection, which are amplified by the amplifier 94 and reproduced
by the speaker 98. In this manner, the user is able to recall both
a portion of the musical selection and the message identifying that
selection. Multiple such selections/messages may be stored,
recalled and deleted using the switches 128, 136, and 138 in
conjunction with the plurality of switches 114 as described above.
A suitable switching arrangement (not shown) can be implemented to
suppress the audio reproduction of received signals from the
network 82 during the playback of the stored audio signals from the
processor 120.
Three protocols were discussed in connection with the transmitter
system 10 relating to the timing of the broadcast of messages with
respect to the broadcast of the musical selections associated
therewith. These protocols included the broadcast of the message
during, prior to, and subsequent to the broadcast of the associated
musical selection. It is presumed that when the message is
broadcast during the broadcast of the musical selection, the
broadcast of the message begins substantially at the beginning of
the broadcast of the musical selection it identifies. The manner in
which the receiver system 70 associates and stores received
messages in conjunction with musical selections is related to the
particular protocol selected for use with the transmitter system
10, as follows.
If the selected protocol is one where the message is broadcast
prior to the broadcast of the associated musical selection, the
processor 120 is configured to store the message contained in the
temporary storage area, along with the portion of the selected
musical selection.
If the selected protocol is one where the message is broadcast
during the broadcast of the associated musical selection, the
processor 120 is configured such that it stores the portion of the
selected musical selection, and scans the temporary storage area
for an EOM code. If one is found, this indicates that the desired
message has been received in its entirety (recall that the
processor 120 clears the temporary storage area upon receipt of an
SOM code), and that message is stored in non-volatile memory in
association with the stored musical selection. If no EOM code is
found, the processor waits until such a code is received, and then
stores that message in non-volatile memory in association with the
stored musical selection.
If the selected protocol is one where the message is broadcast
after the broadcast of the associated musical selection, the
processor 120 is configured such that it clears the temporary
storage area prior to storing the portion of the selected musical
selection, and then scans that storage area for a newly received
EOM code. When that code is received, the message stored in the
temporary area is stored in the non-volatile area in association
with the stored musical selection.
While a first embodiment of the invention has been disclosed,
modifications and additions of the invention has been disclosed,
modifications and additions can be made to provide additional
features. A second embodiment of the invention is provided in which
the auxiliary data in the form of a digital text message is
transmitted during periods of monophonic audio transmission to
enable the use of higher levels of modulation for the transmission
of such data.
As described above, the broadcast station transmits a plurality of
stereophonic musical selections which are separated from each other
by an interval of silence of about one second or more, or are
separated by audio announcements of much longer duration. In this
second embodiment, the broadcast mode during the intervals of
silence or audio announcements is converted to monophonic
transmission as follows, where it is presumed for the purpose of
example that the message broadcast protocol used is that of
broadcasting the message just prior to the associated musical
selection.
Returning to FIG. 1, the start signal for instituting the
transmission of the auxiliary data is provided on the line 60
during the interval of silence or audio announcement just prior to
the stereophonic broadcast of the musical selection identified by
that data. That start signal is also provided on line 154 to
actuate a switch 156 which acts to connect together the left and
right audio input lines 12 and 14. The effect of this connection is
to convert the signals from the audio source to the monophonic
signal, where the left and right channels are equal. In the case
where the interval prior to the broadcast of the musical selection
includes an audio announcement, the audio source may be a
microphone or pre-recorded source. In the case where the interval
is one of silence, there is no signal on the lines 12 and 14, and
the switch 156 may additionally ground these two lines using line
158, to ensure null signals on these audio lines.
It will be appreciated that setting the signals on the lines 12 and
14 equal to each other reduces the L-R signal from the adder 22
(and hence the DSBSC signal on the line 31) to zero. Accordingly,
the stereo pilot signal on the line 40 is not needed for purposes
of receiver stereo demodulation during this interval. As a result,
both the unmodulated amplitude and the level of AM modulation of
the stereo pilot carrier may be increased over those levels used
during stereophonic transmission.
For example, the amplitude of the unmodulated pilot can be
increased by amplifier 42 to a value where it FM modulates the main
carrier at a 20% level as opposed to the 9% level used during
stereo broadcast. Further, the level of AM modulation of the pilot
can be increased to say, 50% of the pilot signal (corresponding to
an FM modulation range of 10 to 30% of the main carrier), as
opposed to the 11% level (corresponding to an FM modulation range
of 8 to 10% of the main carrier) used during stereo broadcast.
The effects of these changes during monophonic broadcasting are
shown in the frequency spectrum by the graph of FIG. 5, which may
be compared to FIG. 2. Note the absence of the DSBSC signal, and
the increase in amplitude and FM modulation levels (line 168) of
the stereo pilot subcarrier. These stereo pilot signal modulation
effects are shown in the time domain by the graph of FIG. 6, which
may be compared to FIG. 3. These changes are accomplished by
providing a steady state bias signal on the line 62 which boosts
the unmodulated pilot subcarrier amplitude to the desired level
during monophonic operation, and providing the pulses representing
the digital message in sufficient amplitude to provide the desired
AM modulation level of the pilot. The result of these changes is to
provide a much higher signal-to-noise level in the transmission of
the auxiliary data, as compared to the first embodiment. These
changes do not adversely affect the operation of conventional FM
stereo receivers, since the stereo pilot is not used or required
for reception of monophonic broadcasts.
While particular amplitude and modulation levels have been
described in relation to the stereo pilot in this configuration, it
is contemplated that other levels may be used as well. For example,
the unmodulated level of the stereo pilot could be further
increased to effect a 30% FM modulation level of the main carrier,
and the AM modulation level may be increased up to 100% of the
pilot signal.
At the completion of the broadcast of the auxiliary data, which
occurs within the monophonic interval, the start signal is removed,
and the transmission reverts back to stereophonic, whereby the
musical selection is broadcast. This same technique can be used
with the protocol where the message is broadcast in the interval
following the musical selection which it identifies.
In a modification of this embodiment, auxiliary data is again
broadcast during monophonic transmission intervals, but the stereo
pilot subcarrier is not used for this purpose. Instead, the 38 kHz
subcarrier generated by the PLL 38 is transmitted in place of the
stereo pilot (the transmission of which is suppressed), and its AM
modulated with the auxiliary data. FIG. 7 shows the modifications
to the system 10 to accomplish this objective. The start signal on
the line 60 in FIG. 1 is used as described above to start the pulse
code generation by the generator 58 and to actuate the switch 156
to set the audio channels 12 and 14 equal to each other. In
addition, this signal is used to control switches 160 and 162 in
FIG. 7 as follows.
The switch 160 is actuated to divert the 38 kHz carrier from the
modulator 30 to the input terminal of the amplifier 42 via the line
40. The switch 162 is actuated to disconnect the stereo pilot
signal from the network 26. In this configuration, the stereo pilot
is not broadcast, and the DSBSC signal on the line 31 is a null
signal as a result of the actuation of the switch 156. The 38 kHz
signal on the line 40 is AM modulated by the amplifier 42 in
response to the signal from the generator 58 on the line 62, and
the resultant signal is provided via the line 44 to the network 26
from where it is used as a subcarrier to FM modulate the main
carrier.
The dotted line 164 in FIG. 5 shows the presence of the 38 kHz
subcarrier in the frequency spectrum of the main carrier during
monophonic broadcasting, while the stereo pilot subcarrier (line
168) would not be present during this time. Since the 38 kHz
subcarrier is not needed as a suppressed carrier for the DSBSC
signal during monophonic broadcasts, it may be broadcast in place
of the stereo pilot subcarrier, which is suppressed, and its
amplitude and AM modulation levels may be set over a wide range of
the signals from the generator 58 in conjunction with the amplifier
42 to broadcast the auxiliary data at high signal-to-noise levels.
Thus the unmodulated level of the 38 kHz subcarrier may be set, for
example, to a 20 to 40% FM modulation level of the main carrier,
and may be AM modulated up to a level of 100%.
FIG. 8 shows the modifications to the receiver system 70 of FIG. 4
to receive and demodulate the 38 kHz carrier. The output signal on
the line 83 from the filter 78 is provided to an AM demodulator 170
which is used in place of, and may be similar in construction to
the modulator 118, but which also includes a disable signal input
terminal which is connected to the line 86 to receive the stereo
pilot signal as a disable signal. The output signal from the
demodulator 170, which represents the pulse code sequence for the
digital message, is provided to the data input terminal of the
processor 120 on the line 119.
During monophonic operation, the absence of the stereo pilot signal
disables the DSBSC detector 84, and enables the demodulator 170.
Accordingly, no spurious audio signals are reproduced by the
speakers 96 and 98 in response to the presence of the 38 kHz
subcarrier, which is demodulated by the circuit 170, and the
resultant message data is provided to the processor 120. This
mechanization also does not disturb the operation of conventional
FM stereo receivers, since the absence of the stereo pilot during
monophonic operation also operates to disable the DSBSC detector 84
in these units.
While the above-described system uses a 38 kHz subcarrier in place
of the stereo pilot to broadcast the auxiliary data during
monophonic transmission, it is envisioned that other subcarrier
frequencies in the spectra above the frequency of the stereo pilot
(19 kHz) and extending to and including the upper frequency of the
DSBSC signal (53 kHz) may be used as well. Further, other amplitude
modulation techniques may be employed to AM modulate the 38 kHz
subcarrier, other than PAM modulation. For example, tone modulation
techniques may be employed where the pulses from the code generator
58 modulate a tone signal which in turn AM modulates the
subcarrier. Such techniques may be employed to decrease the
response time of the circuits used in the AM demodulator 170.
A system for implementing the functions of the data source block 54
and the code generator block 58 in FIG. 1 is shown in FIG. 9. As
described above, the block 54 is used to provide a digital signal
which contains the musical selection identifying data, preferably
in the form of the title, artist and album name relating to that
selection. In FIG. 9, there is shown a compact disc (CD) player 172
used as the source of the stereophonic audio signals provided on
the lines 12 and 14 to the transmitter system 10. Thus a stereo
music selection is broadcast by inserting a particular CD in the
player 172, and selecting a particular track to be played.
The majority of compact discs contain digitized data corresponding
to an album of musical selections performed by a particular artist
or artists. Each of the selections is provided on a separate track,
which is selected by number. The compact disc contains sub-tracks
containing additional data such as the total number of tracks, and
the time duration of each selection. Many CDs also contain a disc
identification number, which can be thought of as an album code,
and which can be used to uniquely identify that disc from other
discs.
The player 172 provides separate output digital signals on the
lines 174 and 176 which contain the track number selected, and the
disc identification data, respectively. These signals are provided
to input terminals of a digital processor 178, which may be in the
form of a mini-computer, to which is connected a memory storage
device 180 which may be in the form of a floppy or hard disk.
Stored in this memory device is a table which lists the album
identification codes for a plurality of CDs, along with the name of
the album and the performing artist. Also stored in this table are
the track numbers for each disc, and the name of the selection
corresponding to that track. It is envisioned that the data in this
table will be updated periodically as new CDs are released.
In response to the signals on the lines 174 and 176, the processor
178 provides a look-up function using the data in the stored table
to determine the album name, artist name and musical selection
title to be broadcast. This data is combined with suitable SOM, EOM
and error correcting codes, which are assembled into the desired
pulse code sequence and amplitudes to be provided to control the
gain of the amplifier 42. In response to the start signal on the
line 60 (also provided to the processor 178), the pulse code
sequence is provided on the line 62 to the amplifier 42.
Another embodiment, shown in FIG. 10, is a system that broadcasts
lyrics information along with audio music. In conventional FM
broadcasting systems, the music is taken from a source such as a CD
player 150 which produces an analog audio signal. The audio signal
is passed through a matrix network 151, such as the one shown in
FIG. 1, and broadcast by an FM transmitter 152. The FM signal
generated by the transmitter is received by an FM receiver 154
which, when it is tuned to the frequency of the transmitter,
converts the FM signal into signals that drive loudspeakers 156,
reproducing the music that originally was produced by the CD
player.
In the system shown in FIG. 10, data regarding the music selection
being played by the CD player is output to a computer 158. This
data includes an identification number that identifies the CD being
played, a track number that identifies the track of the CD that has
been selected to be played and a signal that indicates the time
elapsed from the beginning of the selected track.
Although most CD players utilized by radio stations are able to
send CD and track identification and elapsed time signals to a
computer, some are not. In these cases the CD and track
identification numbers can be input manually into the computer
using the computer's keyboard. The time elapsed signal can be
artificially created by the computer itself if the computer is
signalled with the time the musical selection begins to be played
by the CD player.
A list of a number of CD and track identification numbers can be
entered into the computer at one time in the order in which the
musical selections corresponding to the CD and track data are to be
played by the radio station during a period of time. In such cases,
the radio operator would only have to indicate to the computer when
each musical selection started. After a start indication is
received by the computer, the computer assumes that the next start
signal it receives will be for the next CD and track identification
numbers on the previously entered list of CD and track
identification numbers. Depending on the operation of the radio
station, these CD and track data lists could be entered covering
the music to be broadcast for periods of full days or longer.
The entry into the computer of the start signal could be performed
manually by a key on the computer being pressed when the musical
selection starts. Alternatively, if the CD player provides an
output the indicates that the PLAY, PAUSE, CUE or similar button on
the CD player has been pressed, this output can be sent to the
computer to indicate the start of the musical selection. Another
alternative is to include in the system an audio level meter that
detects a rise in the audio level output by the CD player,
signifying the start of the musical selection being played by the
CD player and sends a signal to the computer indicating this.
Based on the CD and track identification and elapsed time data
received, the computer retrieves lyrics and lyric timing data from
a mass storage device 160 for the music selection contained on the
selected track of the CD. The computer sends the lyrics and lyric
timing data to a subcarrier band signal generator 162, whose output
is combined with the analog audio output from matrix network 151 by
a linear combining network 164 such as the linear combining network
26 shown in FIG. 1. The output of the linear combining network is
then transmitted at the FM frequency of the radio station. The
combined audio and subcarrier signal is received by both standard
FM radio receivers 154 and by lyric display units 166.
The operation of the FM radio receivers is not affected by the
added subcarrier signal. The lyric display unit, on the other hand
receives both the main audio radio signal and the subcarrier
signal. The data broadcast over the subcarrier signal is
interpreted by the lyric display unit, which displays series of
phrases of lyrics. After the words of each phrase of lyrics are
displayed, individual words or lines of words can be highlighted.
Highlighting can be accomplished by underlining, switching
background and foreground colors or shades, using a bouncing ball
or any other highlighting method that the display on the lyric
display unit is capable of implementing. The data output by the
computer and transmitted over the subcarrier band includes signals
that allow the lyric display unit to highlight individual words or
lines in synchronization with the music that is received by FM
receivers tuned to the same radio station. The lyric display unit
also includes a port for outputting the lyric information to a
printer 168 and an ordinary FM receiver that outputs an audio
signal to headphones 170.
FIG. 11 shows an embodiment of lyric display unit 166. The lyric
display unit includes two display screens, a lyrics display screen
172 and a tuning display screen 174. The lyric display screen shown
is a four line by forty character liquid crystal display (LCD), but
could be any suitable display device, including different size
LCDs. The lyric display screen is capable of highlighting certain
words or lines shown on the display. Such words or lines can be
highlighted using methods including, but not limited to
underlining, displaying in bold, or in inverse (e.g. white on black
instead of black on white) and using a "bouncing ball" indication.
The lyric display unit can be capable of different highlighting
methods, which can be selected by the user by pressing the
underline button 175. The tuning display screen shown is a one
line, 40 character LCD and could also be any kind of suitable
display and can be combined as part of display 172 if desired. The
tuning display shows the frequency of the FM station currently
tuned, the call letters of that station and can display the name of
an advertiser that is sponsoring the broadcasting of the
lyrics.
FM stations can be tuned by using the Tune up and down buttons 176.
The tuning frequency for any station can be stored by the listener
in "preset" memory locations similar to those found in most
electronic car radios. A preset memory is set by tuning the station
with the tune up and down buttons 176, pressing the station store
button 178 and then one of the numbered preset buttons 180. FIG. 11
shows a lyric display unit with six presets, by way of example, but
any number of presets can be provided. The preset station can then
be tuned simply by pressing the preset button that was
programmed.
In order to pay for the cost of broadcasting lyric data, radio
stations may sell time on the lyric display to advertisers. Thus,
an advertiser can have a standard audio commercial played over the
radio while simultaneously having critical information such as the
advertiser's name, phone numbers and addresses displayed on the
lyric display. In order to make the display of this information
most useful to the listener, the listener may temporarily store
advertising information in any of the memory locations
corresponding to the preset buttons 180. The listener stores,
retrieves or deletes advertising information using either the INFO
STORE, INFO RECALL or INFO DELETE buttons followed by one of the
six preset buttons 180. The memories used to store advertising
information are distinct from the station preset memories even
though the same numbered preset buttons 180 are used in their
selection.
When advertising information is stored using the INFO STORE button
followed by a preset button, the light emitting diode (LED) above
the preset button pressed is illuminated, or another visual
indicator used, to show that that memory location is occupied. The
user is prevented from storing additional advertising information
in any occupied memory location, i.e. a preset button with its LED
illuminated. An audible indication can also be given to inform the
user that the memory location is occupied. An occupied memory
location can be cleared by pressing the INFO DELETE button followed
by the preset button associated with the memory location to be
cleared. The LED above the preset button associated with the
cleared memory is then extinguished and the memory location is free
to be used for storing other advertising material.
Alternatively, a single LED or audio signal could be used that
would only alert the user when all of the available memory
locations are occupied. The indicator would be extinguish or
disengaged when one of the memories are cleared by the user.
Using the INFO RECALL button followed by a preset with an
illuminated LED displays the information stored in the memory
associated with that preset button on the display of the lyric
display unit. Recalling stored information using the INFO RECALL
button automatically interrupts the receipt of any advertising or
lyrics information being broadcast at that time and the recalled
information is automatically displayed instead of the information
then being broadcast. If there is more information stored in a
memory than can be displayed on the screen at one time, as will
often be the case in embodiments using smaller display screens, the
user may access the non-displayed information by using the SCROLL
UP/DOWN buttons.
An alternative method of storing, recalling and deleting
advertising information involves using only the INFO STORE, INFO
RECALL and INFO DELETE buttons without using preset buttons. In
this method, when a user desires to store the advertising
information displayed on the lyric display unit, he or she simply
presses the INFO STORE button. The lyric display unit automatically
stores the advertising information into the first available memory
location and the LED associated with that memory location is
illuminated. To recall information from memory locations, the user
can repeatedly press the INFO RECALL button, which cycles through
the occupied memories, displaying the advertising information
stored from each occupied memory. When the advertising information
from a particular memory location is currently being displayed,
after using the INFO RECALL button, pressing the INFO DELETE button
will cause that memory location to be cleared and the LED
associated with that memory location extinguished.
Advertising information can also be output to a printer through
printer port 182 when it is received or after being recalled from a
memory by pressing the PRINT button. The lyric display unit also
includes a standard FM receiver with output to a headphone jack
184.
FIG. 12 shows a block schematic of lyric display unit 160. The
lyric display unit receives FM radio signals with receiving antenna
186. The antenna supplies an input to a standard FM tuner chip or
chip set 188. The FM tuner chip 180 tunes to an FM frequency using
a standard frequency synthesizer 190 such as a phase lock loop. The
signal tuned by the FM tuner chip and the frequency synthesizer is
directed to standard stereo audio circuits 192 and a subcarrier
decoder 194. The stereo audio circuits supply audio signals to a
headphone jack 184 so that the listener can listen to the music
being broadcast on the selected FM station. An amplifier capable of
driving loudspeakers could also be included.
Any of a variety of subcarrier techniques can be used to broadcast,
receive and decode the lyrics data, including the subcarrier
broadcasting system shown in FIGS. 1 through 3 and 5 through 8. In
the embodiment shown in FIGS. 10 through 16, the standard, well
known SCA subcarrier band is utilized, including an SCA decoder as
the subcarrier decoder 194. Many other subcarrier techniques may be
used, including the subcarrier described above, but the SCA
subcarrier band is adequate for use in this embodiment. The
subcarrier decoder outputs the decoded data to the central
processor unit (CPU) 196. The CPU includes a read-only memory (ROM)
that stores a program that controls the operation of the CPU. The
CPU and program stored in ROM interpret the data output by the
subcarrier decoder and parse the data into commands and character
data. The commands found in the lyric data are executed to
determine where on the display 198 (display 198 can include both a
lyrics display screen 172 and tuning display screen 174 shown in
FIG. 11) to place the characters represented by the character data.
The commands also direct which characters are to be highlighted and
when. The CPU also stores lyric or advertising data into memory,
such as random access memory (RAM) 200 and can also send the data
to the printer port 202 based upon signals received from the
controls 204 operated by the listener.
Sufficient memory is allotted in RAM 200 to store at least two
phrases of lyrics. This allows one phrase to be displayed from data
already stored in memory while a subsequent phrase is
simultaneously transmitted and stored in a memory buffer. This
architecture avoids the need to rapidly transmit a phrase at the
completion of a previous phrase, as discussed more fully below.
While the lyric display unit 166 is shown as a separate component
used with a receiver 154, it is contemplated that the unit 166 will
be integrated into future models of both portable and stationary FM
stereo receivers. It is also contemplated that the lyric and
advertising text and command format will be made compatible with
the radiotext mode of broadcasting in the SCA band as described in
the Radio Data System (RDS) specification published by the European
Broadcasting Union, 1984, and the corresponding United States
version of that specification, which has not issued as yet and is
entitled "Specification of the Radio Broadcast Data System"
(RBDS).
The lyrics and lyric timing data to be broadcast to the lyric
display unit over the SCA subcarrier band are generated using the
combination of a CD player 210 and a computer 212 shown in FIG. 13.
The CD player 210 used in the preferred embodiment is a Studer A730
Professional Compact Disc Player. The computer can be any personal
computer but is an IBM-compatible personal computer, including RAM
memory, a hard disk drive and a display in the preferred
embodiment.
Compact discs store analog music as digital information, that is as
a series of 1's and 0's. This format allows the easy embedding of
control information such as album identification numbers, track
numbers and elapsed time with the digital representation of the
music. Compact discs are divided up into many "frames" of
information. The format of each frame is identical and contains a
predetermined amount of digital information, including both audio
data and control data. Seventy-five frames contain the information
for each second of audio material stored on a compact disc. Frames
within a certain track are referred to by their sequence in time
from the beginning of the track expressed as a six digit decimal
code: two digits for minutes, two digits for seconds and two digits
for frames. Each frame on a compact disc includes such a six digit
code in its control data, uniquely identifying the particular
frame. More details regarding the coding of compact disc can be
found in the International Standard for the "Compact disc digital
audio system," published by the International Electrotechnical
Commission (CEI IEC 908, 1987).
The Studer A730 Professional Compact Disc Player includes a data
output port that is connected to the computer. The data output to
the computer on this port includes the album identification number,
track number and the minute, second and frame data read for each
frame on the compact disc as the disc is being played. The album
identification number is provided in a subcarrier channel on the CD
as described in the International Standard.
The actual creation of the lyric and lyric timing data is as
follows. The first step is to either manually enter the lyrics into
the computer or obtain the lyrics in computer readable form from
another source, such as the artist or music publisher. The lyrics
are then split into phrases, generally from three to ten words, so
that the entire phrase can be displayed at one time on the display
screen 172 of the lyric display unit. If a phrase buffer as
described above is not employed, the phrases should also be
selected so that, if possible, about a half second pause in the
music coincides with the breaks between phrases.
Once the phrases are determined, the second step is begun by
playing the CD on the professional CD player. The Studer CD player
allows the music to be listened to at adjustable speeds, if
necessary, allowing the user to pinpoint the actual frame in which
each word of the lyrics are begun to be sung. It is sometimes
important to determine the lyric timing down to the frame level of
detail (1/75 of a second) because certain music, particularly rap,
often averages four words or more per second throughout an entire
musical selection. Once the beginning of a word is detected by the
listener, the listener signals the computer that the word has begun
to be sung. The computer automatically stores the minute, second
and frame data from the timing output signal of the CD player and
associates this information with the word that is being sung. The
second step is repeated until timing data is stored for every word
in the musical selection.
By using this process, lyrics files that include phrasing and
timing data for any musical selection can be generated using the
computer and CD player combination. An example of how this
information can be stored is shown below. The beginning of each
phrase is denoted by a tilde (.about.). The end of each line within
a phrase is denoted by an "at" symbol (@). The end of each phrase
is denoted by a caret (), while the end of each word is denoted by
a vertical bar (). Thus the phrasing data for "Mary had a Little
Lamb" may look like the following:
.about.Mary had a little lamb@
little lamb little lamb
.about.Mary had a little lamb@
whose fleece was white as snow
Timing data can be added by inserting a number consisting of the
six digit minute, second and frame received from the compact disc
player, with leading zeros deleted after each word of the lyrics,
separated by another vertical bar () and with a space before the
number to distinguish timing numbers from lyrics that happen to be
numbers. Thus the phrasing of Mary had a Little Lamb including time
data may look like the following:
.about.Mary 448 had 524 a 552 little 73 lamb@ 648
little 723 lamb 773 little 848 lamb 923
.about.Mary 973 had 1048 a 546 little 1122 lamb@ 1173
whose 1227 fleece 1248 was 1301 white 1323 as snow 1373
FIG. 10 shows how the lyric and timing data is transmitted to the
lyric display unit. When a CD is cued for broadcast, the album
identification number and track number of the CD are output from
the CD player 150 to the computer 158. The mass storage device 160
connected to the computer contains lyric and timing data files for
a large number of musical selections. These files are indexed by
album identification number and track number. Thus, when the album
identification number and track are received by the computer from
the CD player, the lyric and timing file for that musical selection
can be quickly found and retrieved.
As described above with respect to FIG. 10 and the broadcasting of
the lyric data, if the CD player being used in conjunction with the
creation of the lyric and timing data files does not output the CD
identification and track numbers and the elapsed time data this
data can be entered into the computer by other methods. The CD
identification and track numbers can be entered manually using the
computer keyboard. The elapsed time can be calculated by the
computer from a start signal obtained through the computer's
keyboard, a PLAY, PAUSE, CUE or other operational status signal
received from the CD player, an audio signal meter connected to the
output of the CD player or any other way to detect the start of the
musical selection.
Once the correct lyric and timing file is accessed, the computer
must generate and transmit commands and data that will be
interpreted by the lyric display unit to properly display the
lyrics and the highlighting. The commands and data are output by
the computer to the SCA generator phrase by phrase.
As soon as the lyric and timing file is retrieved, the text data
for the first phrase is sent to the SCA generator. The text data
includes command codes indicating the start of the phrase, the
separation of the individual words within the phrase, breaks
between the lines of text within the phrase and the end of the
phrase. Thus, the lyric display unit, upon receiving this data, can
determine how many words are in the received phrase. The computer
158 then monitors the minute, second and frame output of the CD
player. When the minute, second and frame match the minute, second
and frame of the first word of the current phrase, a "highlight"
command is generated and sent through the SCA generator to the
lyric display unit, which highlights the first word of the phrase
as soon as the code is received. When the minute, second and frame
data from the CD player matches the minute, second and frame of the
second word in the current phrase, another "highlight" command is
generated and broadcast to the lyric display unit which then
highlights the second word of the phrase it received. This process
is repeated until the highlight command is generated for the last
word of the current phrase. When the entire phrase has been
highlighted, the computer then repeats the whole process by sending
the text data for the next phrase through the SCA generator and to
the lyric display unit.
Alternatively, and preferably, the data for a subsequent phrase is
formatted and transmitted prior to the time of completion of the
present phrase, and is stored in a suitably provided buffer in the
lyric display unit. After the complete subsequent phrase has been
broadcast to the lyric display unit and the highlight command for
the last word of the current phrase has been broadcast, but before
the time for broadcasting the highlight command for the first word
or line of the subsequent phrase, a "change phrases" command is
broadcast. Upon receipt to the "change phrases" command, the lyric
display unit clears the present phrase from memory and the display,
displays the subsequent phrase, and either transfers the data for
the subsequent phrase from the phrase buffer to the memory for the
present phrase or simply swaps the locations of the present phrase
memory and the phrase buffer. At this point the subsequent phrase
becomes the present phrase and the process is repeated until the
end of the musical selection.
In an alternative method of broadcasting the lyric text data and
lyric timing commands, when the lyric and timing file is retrieved,
the text data for the first phrase is sent to the SCA generator.
The text data includes command codes indicating the start of the
phrase, the separation of the individual words within the phrase,
breaks between the lines of text within the phrase and the end of
the phrase. The text data also includes commands that direct the
highlighting of the individual words or lines by the lyric display
unit. Included for each word in the phrase or for each line of the
phrase is command that includes an offset time. The offset time is
the length of a delay that should occur from the receipt by the
lyric display unit of a timing signal, corresponding to a
predetermined reference point in time, and the time when the lyric
display unit highlights the word or line. Using the "Mary had a
Little Lamb" example from above, the highlight command code could
include "448" (four seconds and 48 frames or 4 and 48/75 seconds)
indicating the time after the start of the song that the word
"Mary" is to be highlighted. If this scheme is used, a "start"
signal must be sent to the lyric display unit at the exact time
when the song begins to be played by the CD player. The lyric
display unit is then responsible for comparing the highlight
command with an internal clock and the time when the "start" signal
was received by the lyric display unit to determine when each word
should be highlighted. It is important to note that the text data
of any phrase can be transmitted before or after the "start" signal
is transmitted. In the "Mary had a Little Lamb" example, the
"start" signal could be broadcast before the first phrase, provided
that the text data for the first phrase is broadcast at least
within 4 48/75 seconds of when the "start" signal is broadcast.
Accordingly, subsequent phrases can be broadcast at any time before
the first word in the phrase needs to be highlighted. Of course,
the timing signal can be associated with any predetermined temporal
reference point that occurs before the first word of lyrics with
which the reference point is used for highlighting purposes.
Data can routinely be transmitted over the SCA band at a rate of
about 2400 bits of data per second. At this rate, four full forty
character lines can be transmitted in about one-half of a second.
Therefore, when a phrase buffer is not used and the phrasing of a
particular musical selection is being determined, efforts should be
made to have the breaks between phrases coincide with periods in
the musical selection without lyrics of at least a half of a
second.
Again though, an alternative and preferable method is to employ the
phrase buffer described in detail above, so that after one phrase
of lyric text and timing commands has been broadcast and being
currently displayed by the lyric display unit, the next phrase of
lyrics and associated timing commands can be broadcast to the lyric
display unit and stored in its display buffer until the current
phrase is completed. Using this method eliminates the need to be
concerned about parsing lyrics into phrases so that there are half
second pauses between phrases.
Another subtlety in broadcasting the highlight commands is that the
comparison between the minute, second and frame output by the CD
player and the minute, second and frame in the lyric and timing
file should be performed taking into consideration that there is a
small, but constant delay between the receipt of the timing data
from the CD player and the generation, broadcast, receipt and
processing of the highlight commands. This delay should be
subtracted from the minute, second and frame data from the lyric
and timing files before comparison to the CD player generated data
so that highlighting occurs in synchrony with the music and does
not suffer from a slight lag.
A problem with the lyric display system described above is that
most advertisements are not supplied to radio stations on compact
disc or in any other digital format that includes provisions for
embedding data. As shown in FIG. 14, commercials are usually
supplied to the radio station on reel-to-reel magnetic tape 220.
Radio station personnel then transfer the commercials from the
reel-to-reel tape onto analog magnetic endless tape cartridges 226
("carts") that are used on standard radio station audio tape
cartridge ("cart") machines 224 such as the ITC Delta series of
recorders and reproducers, distributed by Harris Allied
International, Richmond, Ind.
A solution to this problem is disclosed in the system shown in
FIGS. 15 and 16. The analog magnetic tape cartridge systems that
are standard in radio broadcasting include a cuing track on which
cuing signals, consisting of various audio tones, are placed. This
system is described in detail in the National Association of
Broadcasters Specification for Cartridge Tape Recording and
Reproducing, 1976. Each radio station adds its own cuing signals
because radio stations have widely varying procedures regarding
pauses, delays and other logistical details regarding the playing
of commercial advertisements.
In the system shown in FIGS. 15, a computer 228 is connected so
that it can control the operation of both the reel-to-reel tape
machine 222 and the cart machine 224. Alternatively, the
reel-to-reel tape machine can control both the cart machine and the
computer with similar results. The advertiser supplies both a
reel-to-reel tape 220 containing the audio portion of the
commercial as usual, but also supplies a floppy diskette 230 that
contains the text to be displayed on the lyric display unit. The
computer 228 can then, using a digital to analog converter, store
the text to be displayed and any commands that need to be
transmitted to the lyric display unit onto the standard cuing track
of the cart. Since the computer can control both the reel-to-reel
tape machine and the cart machine, the computer can have the audio
portion of the commercial transferred to the cart machine
simultaneously with the transfer of the analog coded advertising
text.
The broadcasting of advertisements recorded in this way are
performed by the system shown in FIG. 16. The computer 232 is
controlled by the cart machine 234 using a control line. When an
advertisement is being played from a cart, the cart player alerts
the computer through the control line. The computer then monitors
the cue channel and upon detecting text and commands for use with a
lyric display unit, these commands are converted back to digital
form, output to the SCA generator and broadcast to lyric display
units.
A variation of the system shown in FIGS. 15 and 16 does not affect
the hardware connections of the system. However, instead of the
text and display commands being converted to analog and stored on
analog tape, a unique commercial identification code can be
converted into analog tones and placed on the cuing track. The text
and display commands for all commercials are then stored on a mass
storage device, indexed by the commercial identification code. When
an advertisement is then played on cart machine 234, only the
unique commercial identification number needs to be detected by the
computer and converted from analog to digital. The computer's index
is searched for the entry corresponding to the unique commercial
identification number received from the cart machine and the text
and display commands stored on the computer's mass storage are
retrieved by the computer and output to the SCA generator and
broadcast in the same manner as described above.
Another variation of the system shown in FIGS. 15 and 16 does not
utilized the cuing track of the carts to store data. A list of the
unique commercial identification codes corresponding to the
commercials to be aired during a period of time can be entered into
the computer all at one time in the order in which the commercials
corresponding to the commercial codes are to be aired. Similarly to
the embodiment described above where a list of data regarding music
selections to the aired are entered into the lyric generating
computer, the operator only has to indicate to the computer when
each commercial begins. After the computer receives a start
indication for the current commercial on the list, the computer
will output the supplemental data as in the systems described above
and assumes that the next start signal it receives will be for the
next commercial on the list that was entered into the computer. The
start signal does not have to be manually entered, but similarly to
the lyric generating system, could consist of a cuing signal
received from the cart machine playing the commercials or an audio
level meter connected to the audio output of the cart machine that
detects the beginning of a commercial.
This system described immediately above for commercials can also be
combined with the similar system described above for generating
lyrics text and timing data based on a pre-entered list of data for
musical selections to be played. A computer is simultaneously
connected both as the system shown in FIG. 10 and as the system
shown in FIGS. 15 and 16. A combined list is created that lists
album identification and track numbers and commercial
identification codes in the order that corresponding music and
commercials are to be aired. Similar to the separate lyric and
commercial systems, the operator would indicate to the computer the
time whenever either a music selection or a commercial began.
Alternatively, audio level meters or signals from the CD player and
cart machine could be used to signal the computer as to the start
of music selections or commercials in the same manner as in the
individual lyrics and commercial systems described above. When the
computer receives a start signal, it outputs the appropriate lyric
text and timing data for music selection or the appropriate
supplemental advertising data for commercials and waits for the
next start signal that will correspond with the beginning of the
next music selection or commercial on the combined list stored in
the computer.
While there have been shown and described preferred embodiments of
the present invention, it is not intended that the invention be
limited solely to these embodiments. It is therefore to be
understood that because various other embodiments may be devised by
those skilled in the art without departing from the spirit and
scope of the invention, it is the intention of the inventor to be
limited only by the claims appended hereto.
* * * * *